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Date: Tue, 5 May 2015 19:27:42 +0200
From: Michael Scherer <>
Subject: Local privileges escalation in rubygem open-uri-cached 


open-uri-cached, a rubygem that will cache downloaded data when using open-uri, is 
suceptible to a local attack due to usage of YAML in a insecure way, and using
a predictable directory name in /tmp for getting that data without verification, see

So someone could create ahead of time a directory /tmp/openuri-$someuid/, precreate directory
for the host to contact and with proper permissions, wait until a meta file is created, and
replace it with one containing ruby code to be executed, as it doesn't use safe loader for yaml
( ).

The gem is pulled by various projects on github, the likely most important being
a redmine plugin : 

Could a CVE be assigned ? I will take care of opening a issue on github  for that
after :

Michael Scherer

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